The human papilloma (wart) virus remains the only virus known to produce tumors in man. The possibility that the wart virus may cause more serious neoplasia in tissues other than skin cannot be discounted. Therefore, the overall objective will be to determine whether wart viral DNA sequences exist in cells derived from patients with various benign and malignant tumors. These will include laryngeal papillomas, mucosal papillomatosis, and other tumors such as nasopharyngeal carcinomas. Since a number of human papovaviruses recently have been isolated, it also will be of interest to determine if they have any genetic relationship to the wart virus. The experimental approach will be to analyze cellular DNA derived from various tumors for wart viral DNA sequences. In other studies, the relationship of human wart virus and other human papovaviruses (BK, JC and PML) will be analyzed by DNA-DNA hybridization. For these studies "nicked" wart viral DNA will be labeled in vitro with H3-thymidine triphosphate and DNA polymerase to make a highly radioactive DNA probe. Detection of wart viral DNA sequences in diseased cells in some type of "carrier" state after onset of disease would be of great interest. This situation exists in certain "transformed" cells carrying papovaviruses known to be oncogenic for animals.